A common problem for antenna designers is the integration of low-profile antennas into complex objects such as vehicles or aircraft, while maintaining the desired radiation characteristics. The radiation pattern of an integrated antenna is the result of currents in both the antenna and the surrounding structure. In Prior Art, as shown in FIG. 1a, a flat metal sheet 15 excited by a quarter wavelength monopole antenna 16 produces a low gain (about 5 db) radiation pattern in the metal sheet 15 as shown in FIG. 1b. Therefore, controlling the radiation from currents generated in metal surfaces like metal sheet 15 can expand the available design space.
According to the present disclosure, artificial impedance structures may provide a more controllable radiation pattern than previous conformal antennas, by configuring the metallic surface to provide scattering or guiding properties desired by the antenna designer. According to the present disclosure, artificial impedance structures may be designed to guide surface waves over metallic surface and to ultimately radiate energy to produce any desired radiation pattern.